tbuckley/cabot-search huggingface dataset:
P22 Fibrosis in delayed wound healing in diabetes: the role of insulin-like growth factor binding proteins
Authors: Sharlene Were, Taryn Wilson, Patricia Martin, Catherine Wright
Journal: British Journal of Dermatology (2023)

Abstract Skin fibrosis is thought to be a factor in delayed wound healing in people with diabetes. Insulin-like growth factor binding protein 5 (IGFBP-5), which is fibrotic in other organs, is augmented in the skin of people with diabetes. We examined the effects of IGFBP-5, connective tissue growth factor (CTGF) and transforming growth factor (TGF)-β1 on skin fibrosis and wound-healing capacity in human primary dermal fibroblasts from people with and without diabetes. In vitro scrape wound closure in diabetic dermal fibroblasts was delayed in diabetic fibroblasts. IGFBP-5 treatment further retarded scrape-wound closure rates above that seen with diabetic fibroblasts. Diabetic fibroblasts were more adhesive to substrates than normal fibroblasts in adhesion assays, reducing their migratory capacity, and normal fibroblasts treated with IGFBP-5 and TGF-β1 showed increased adhesion over controls. Diabetic fibroblasts also had reduced cell viability. Fibronectin and collagen production by fibroblasts were increased with IGFBP-5 in cultures; thus upregulated IGFBP-5 in diabetic skin may increase extracellular matrix (ECM) deposition. IGFBP-5 and α-smooth muscle actin protein was overexpressed in diabetic fibroblasts by Western blotting, so IGFBP-5 induces fibroblast to myofibroblast transition. Gene expression of matrix metalloproteinase (MMP)-1, MMP-9, CTGF and tissue inhibitor of metalloproteinase 1 (TIMP-1) was raised in diabetic fibroblasts; MMP-9, MMP-1 and TIMP-1 expression levels were increased with IGFBP-5 treatment. Elevated levels of IGFBP-5 and CGTF in the dermis may contribute to retarded wound healing and ulceration in people with diabetes (despite increases in fibroblast MMPs), causing fibroblasts to lay down more ECM, contributing to fibrosis and compromising the wound bed. Diabetic dermal fibroblasts are compromised in viability and migratory capacity, and are more adhesive and stiffer, making it more difficult for them to populate granulation tissue. They are thus less able to close wounds and hyperproliferate around wound edges. IGFBP-5 and CTGF could be novel therapeutic targets to mitigate diabetic skin fibrosis and improve wound healing.
P14 Whole-genome sequencing of malignant cylindroma in <i>CYLD</i> cutaneous syndrome reveals a clinically targetable somatic driver mutation
Authors: William Fostier, Ching Chiek Koh, Akhtar Husain, Shirin Namini, Serena Nik-Zainal, Neil Rajan
Journal: British Journal of Dermatology (2023)

Abstract Metastatic malignant cylindroma (MC) is a rare skin appendageal cancer for which there are no licensed chemotherapeutic interventions and has poor clinical outcomes. MC arising in CYLD cutaneous syndrome (CCS) has been shown to carry pathogenic variants in CYLD and additional driver mutations in TP53. Here we present whole-genome sequencing (WGS) data from MC in a 29-year-old man, revealing a novel clinically targetable somatic driver mutation. The proband presented with a growing, ulcerated cylindroma on the scalp at 28 years of age. He had previously presented with benign cylindromas on the scalp from 8 years of age, attributed to his mother who had CCS. The proband's father and paternal grandmother both had early breast cancer. The proband's sister, aged 33 years, had been recently diagnosed with breast cancer and CCS. Histology of the ulcerated scalp tumour revealed a biphasic neoplasm, showing malignant cylindroma with high-grade features arising within a pre-existing benign cylindroma. Several weeks following excision of the malignant scalp cylindroma, a nodule presented on the left side of the patient's neck; biopsy of the neck lump revealed histology consistent with the metastatic MC. Radiological imaging revealed metastatic deposits of MC in the right axilla, both lungs and the brain. Genetic testing of the proband revealed germline pathogenic variants in both BRCA2 and CYLD, also present in his sister. WGS of the primary MC showed extensive copy number variation, with loss of heterozygosity involving CYLD and BRCA2 loci, not present in a matched control blood sample. Mutational signatures SBS3 and SBS8 were present, consistent with homologous repair (HR) deficiency, and, in addition, SBS13 was detected, suggesting APOBEC-driven mutagenesis. A high HR detect score of 0.999 was reported, consistent with a BRCA-deficient tumour. Additional driver somatic variants in TP53 and PTEN were also detected and are likely to have contributed to tumour pathogenesis. The BRCA deficiency demonstrated in this patient's MC supports the use of poly ADP ribose polymerase (PARP) inhibitors, which have not previously been used to treat MC. This case emphasizes the importance of recognizing coinheritance of tumour suppressor genes in rare genetic conditions, and the utility of rapid WGS to provide novel management options and improve patient outcomes.
P08 Dissection of the molecular and cellular heterogeneity of dermal fibroblasts in skin fibrosis
Authors: Abubkr Ahmed, Thomas Kirk, Laura  Forster, Edel  O’Toole, Himadri Gupta, Emanuel  Rognoni
Journal: British Journal of Dermatology (2023)

Abstract Skin fibrosis, a common scarring condition that currently has no curative treatments, is caused by persistent activation of fibroblasts after tissue injury or inflammation that results in excessive connective tissue deposition, leading to severe disability, organ malfunction and increased morbidity. This study aims to uncover the early and advanced changes in different fibroblast subsets and molecular pathways that are integral to pathological fibroblast activation using a bleomycin-induced skin fibrosis mouse model that recapitulates well the human disease. We have shown that 2 weeks (early) and 4 weeks (advanced) of subcutaneous bleomycin injections result in an increasing severity of skin fibrosis, characterized by increased dermal thickness, collagen deposition, inflammation, and loss of dermal fibroblasts and adipocytes. We performed single-cell RNA sequencing and successfully isolated 14 944 control, 16 344 early and 6860 advanced fibrotic cells. We identified the changes in fibroblast subclusters and gene signatures that are altered across the time course. Using CellChat, we are dissecting the specific signalling crosstalk between different fibroblast subpopulations and other skin cells, promoting a profibrotic phenotype and locking fibroblasts in an activated state. Furthermore, we are intersecting our novel data set with publicly available wound healing transcriptomic data, allowing us to examine how fibroblast subpopulations, behaviour and key signalling pathways vary in healthy wounding healing and pathological scarring. To understand the impact that changes in extracellular matrix biomechanics elicit on profibrotic fibroblast fate, we are correlating our histological and transcriptomic analysis with nanoindentation atomic force microscopy imaging throughout the fibrotic time course. This novel multidisciplinary approach allows us to compare the cellular and molecular changes in early and advanced fibrotic lesions, identifying the key fibroblast subpopulations, molecular regulators and connective tissue alterations promoting fibrotic tissue repair. Our findings will support the development of new fibroblast-targeted fibrosis therapies in skin and potentially other organs.
O17 Endogenous double-stranded RNA (dsRNA) in melanoma: an attack from within
Authors: Shaymaa Sadeq, Ruth Plummer, Suwalak  Chitcharoen, Penny Lovat, Glyn Nelson, Andreas Werner
Journal: British Journal of Dermatology (2023)

Abstract Recent studies have linked endogenous double-stranded RNA (dsRNA) to the development of inflammatory and autoimmune diseases and cancer. However, the scale of dsRNA formation and its biological consequences is still unclear. Malignant melanoma is the most lethal skin cancer, with an increasing prevalence worldwide. Despite the development of immunotherapy and targeted therapies for melanoma, treatment options are still limited for most patients. dsRNA derived from repetitive DNA elements has the potential to stimulate pattern recognition receptors (PRRs). These PRRs can trigger antiviral signalling cascades and induce an interferon response that renders resistant melanoma sensitive to immunotherapy. Consequently, dsRNA can add a new approach to treating melanoma. Tissue culture and molecular biology techniques were used to induce dsRNA formation in melanoma cell lines (with different mitogen-activated protein kinas-activating mutations) using PRRs agonist poly (I:C), azacitidine (Aza) and hydrogen peroxide (H2O2) as stressors. The impact was measured by quantifying cytosolic dsRNA sensors, also known as PRRs (pPKR, MDA5, RIG1 and ADAR1), using reverse transcriptase quantitative polymerase chain reaction and Western blotting. Immunofluorescence and high-resolution microscopy were then applied to investigate dsRNA and its sensors in skin biopsy samples from patients with melanoma. Moreover, the nature of dsRNA in melanoma was studied by isolating native dsRNA from multiple melanoma cell lines by immune enrichment followed by RNA sequencing. Analysis revealed that inducing endogenous dsRNA significantly activates PRR transcripts and protein levels. However, this activation showed different trends. A375 (BRAFV600E) showed robust MDA5 and RIG1 stimulation to poly (I:C) and a mild ADAR1 and PKR response to Aza and H2O2. Meanwhile, C8161 [BRAF wild type (WT)] was resistant to poly (I:C) with a favourable ADAR1 and RIG1 response to Aza. Immunofluorescence analysis of early stages I and II melanoma skin biopsies showed a significant reduction in ADAR1, which melts dsRNA, with increased dsRNA within BRAF-mutant biopsies. RNAseq analysis showed that A375 (BRAFV600E) produced significantly more dsRNA than C8161 (BRAF WT) and primary dermal fibroblasts. The increase was predominantly due to the enhanced production of dsRNA from nuclear DNA. However, about 11% of the reads mapped to the mitochondrial genome vs. 14% and 19% in C8161 and fibroblasts, respectively. In addition, compared to primary dermal fibroblasts, the dsRNA transcriptome of melanoma cell lines shows unique characteristics and altered dsRNA signalling pathways. To summarize, our data support the hypothesis that endogenous dsRNA activates dsRNA sensors and triggers innate immune signalling. Hence, dsRNA signalling may be explored as a potential therapeutic strategy to treat resistant melanoma with an attack from within.
P12 Tetrapeptide matrikines synchronize circadian rhythms and promote proliferation in human skin cells
Authors: Zeyad El-Houni, Alexander Eckersley, Mike Bell, Eleanor Bradley, Victoria Newton, Michael  Sherratt, Qing Jun Meng
Journal: British Journal of Dermatology (2023)

Abstract Circadian rhythms are intrinsically generated 24 h rhythms that play a vital role in enabling the skin to adapt temporally to various external stimuli. These include ultraviolet radiation, physical trauma and water loss. At the molecular level, circadian clocks consist of various clock genes and proteins, including Per2/Cry1 and Bmal1/Clock, forming autoregulatory feedback loops. Although these rhythms are known to be impaired in ageing skin, there are limited therapeutic options to restore skin cell circadian function. As small peptides with homology to amino acid sequences found in extracellular matrix proteins (matrikines) can beneficially affect clinical and histological markers of skin ageing, in this study we characterized the ability of two novel tetrapeptides to influence the cellular circadian clocks of skin cells. HaCat keratinocytes transduced with a human Per2::luc promoter-driven reporter were used to monitor the effects of two synthetically generated peptides, GPKG and LSVD, on the cells’ intrinsic circadian clock. Following administration of these peptides at various concentrations (4–16 ppm), the oscillatory activity of the cells was amplified up to twofold vs. the vehicle control. LSVD was found to induce Per2::luc promoter activity significantly (P &amp;lt; 0.05). In addition to enhancing circadian rhythmicity, both peptides were assessed for their proliferative effect (by Incucyte imaging and MTT cell proliferation assays). At the higher concentrations tested, both GPKG and LSVD significantly increased proliferation in HaCat keratinocytes (P &amp;lt; 0.05). In conclusion, these peptides have been found to be highly effective in synchronizing the circadian clock in skin cells, leading to changes in their behaviour. This implies that these new peptides may have beneficial effects on skin cells, in part, by improving their circadian function. Given the findings of clock disruption in a number of diseases, as well as with age, identifying compounds that can reset the clock in skin cells is an important approach to developing treatments that can improve the functioning of cutaneous physiological processes that are under circadian control. Funding sources: this study was funded by the No. 7 Beauty Company.
More than skin deep: getting on the same page for mental health in children and young people with skin conditions
Authors: Hsi Yen, Yvonne E Chiu
Journal: British Journal of Dermatology (2023)

Journal Article Corrected proof More than skin deep: getting on the same page for mental health in children and young people with skin conditions Get access Hsi Yen, Hsi Yen Department of Dermatology, Chang Gung Memorial Hospital, Linkou, Taoyuan, TaiwanCollege of Medicine, Chang Gung University, Taoyuan, TaiwanDepartment of Dermatology, Division of Pediatric Dermatology, Medical College of Wisconsin, Milwaukee, WI, USA https://orcid.org/0000-0002-2649-2563 Search for other works by this author on: Oxford Academic Google Scholar Yvonne E Chiu Yvonne E Chiu Department of Dermatology, Division of Pediatric Dermatology, Medical College of Wisconsin, Milwaukee, WI, USADepartment of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA Correspondence: Yvonne E. Chiu. Email: ychiu@mcw.edu https://orcid.org/0000-0003-2869-2718 Search for other works by this author on: Oxford Academic Google Scholar British Journal of Dermatology, ljad232, https://doi.org/10.1093/bjd/ljad232 Published: 07 July 2023 Article history Received: 30 June 2023 Accepted: 04 July 2023 Published: 07 July 2023 Corrected and typeset: 08 August 2023
P02 Potential for the loss of endothelial AMBRA1 expression in the tumour microenvironment to identify high-risk patient subsets with nonulcerated AJCC stage I/II melanoma
Authors: Roisin Stout, Katie Best, Ioana Cosgarea, Penny  Lovat, Jane Armstrong
Journal: British Journal of Dermatology (2023)

Abstract With the recent inclusion of adjuvant therapy for the management of patients with AJCC stage II melanomas there is increased emphasis on the identification of both prognostic and companion biomarkers for early-stage tumours. The expression of AMBRA1 and loricrin (AMBLor) in the epidermis overlying early-stage nonulcerated primary melanomas has recently been identified as a prognostic biomarker able to identify genuinely low-risk tumour subsets. Pilot data also show that loss of AMBLor is associated with loss of AMBRA1 expression in the surrounding tumour endothelium. The aim of the present study was therefore to define the potential of endothelial AMBRA1 expression to identify AJCC stage I/II melanomas at risk of metastasis. Endothelial AMBRA1 expression was determined in a cohort of 48 AJCC stage I/II melanomas previously subjected to automated immunohistochemical analysis for AMBRA1 expression and defined as tumours with loss of AMBLor. Endothelial AMBRA1 expression determined by positive pixel count using Aperio Image-Scope and normalized to vessel area, revealed variable AMBRA1 expression in the intra- and/or peritumoral vessels within 500 µm of the tumour mass. Further analysis revealed a significantly increased proportion of intra-/peritumoral vessels (23.7%) with low AMBRA1 (&amp;lt; 50% of mean total vessel expression) in melanomas that metastasized vs. 12.4% of vessels with low AMBRA1 expression in tumours that remained localized (P = 0.002). Kaplan–Meier analysis additionally demonstrated a significant reduction in 5-year recurrence-free survival (RFS) to 33% for patients with melanomas with &amp;gt; 12% intra-/peritumoral vessels with reduced AMBRA1 expression vs. 76% RFS for patients with &amp;lt; 12% intra-/peritumoral vessels in which AMBRA1 expression was reduced (hazard ratio 5.16, 95% confidence interval 2.05–13; P = 0.003). Collectively, these data suggest that endothelial AMBRA1 expression may serve as a prognostic and companion biomarker to identify and stratify high-risk subsets of patients with early-stage melanoma for adjuvant treatment.
O02 Neoantigens from actinic keratosis are predicted to be more immunogenic than those from cutaneous squamous cell carcinoma – a strategy for immune escape?
Authors: Jason Thomson, Catherine Harwoood, Jessica  Strid, Eugene Healy, Jun Wang
Journal: British Journal of Dermatology (2023)

Abstract Actinic keratosis (AK) is a precursor of cutaneous squamous cell carcinoma (cSCC). More than 70% of cSCC arise from AKs, but fewer than 0.6% of AKs progress to cSCC. We have shown that the molecular landscapes of AK and cSCC are similar in terms of tumour mutational burden (TMB), copy number burden, mutational signatures and driver gene mutations but differ in levels of intrasample heterogeneity. We have also demonstrated that alterations in signalling pathways, including transforming growth factor-β, may be important for AK-to-SCC progression. However, the pathomechanisms underlying progression are not well characterized and it remains unclear why the majority of AKs do not progress, and most will regress. There is some evidence that differences in the neoantigen landscapes of AK and cSCC may play a role, and a previous study examining neoantigens in AK and cSCC from nine patients was the first to suggest that there is downregulation of the expression of highly immunogenic neoantigens in the immune escape of cSCC. In this study we further explore, in a larger data set, the hypothesis that the neoantigen recognition potential of AK vs. cSCC is a key determinant of AK-to-cSCC progression. We generated exome and transcriptome data from AK (n = 5) and cSCC (n = 15) with matched normal exome data (from blood). Human leucocyte antigen typing was performed using the OptiType algorithm and neoantigens restricted to major histocompatibility complex (MHC) class I were predicted using the NeoPredPipe workflow. Fitness of neoantigens, defined as the overall effectiveness of a neoantigen at stimulating an immune response, was determined by combining measures of MHC binding affinity and T-cell receptor recognition potential for the predicted neoantigen, and an overall neoantigen recognition potential score was derived for each neoantigen. The difference in median total neoantigen burden for AK and cSCC was not statistically significant [11 224 (range 30–17 330) and 1680 (range 3159–67 357), respectively (P = 0.07)]. Neoantigen burden was strongly correlated with TMB in both AK and cSCC. We found that, compared with cSCC, AK had predicted neoantigens with significantly higher mean MHC-binding affinity (P = 0.049), mean T-cell receptor recognition potential (P = 0.0093) and overall neoantigen recognition potential (P = 0.02). Taken together, our results confirm that neoantigens in AKs are predicted to be more effective at eliciting an immune response than those in cSCC. This suggests there may be a selection pressure in AKs for mutations that result in fewer immunogenic neoantigens resulting in immune escape and progression to cSCC. Finally, our results underscore the critical requirement for an intact immune system in prevention of AK-to-cSCC progression.
O13 JAK inhibitors to restore skin barrier function in ARCI
Authors: Elena Giusto, Florence Enjalbert, Emanuel  Rognoni, Matthew Caley, Edel  O’Toole
Journal: British Journal of Dermatology (2023)

Abstract The autosomal recessive congenital ichthyoses (ARCI) are a group of chronic conditions where there is unmet therapeutic need. Harlequin ichthyosis (HI) is the most severe form of ARCI, with aberrant differentiation of the epidermis leading to a severe barrier defect. It is caused by mutations in ABCA12, a lipid transporter involved in the transport of glucosylceramides from the lamellar body to the lipid lamellae. Lamellar ichthyosis is caused by mutations in TGM1. Several Janus kinase (JAK) inhibitors (JAKi) inhibiting the JAK–STAT pathway are now licensed for atopic dermatitis. Previous work from our group in an in vitro HI model showed that tofacitinib had a restorative effect on the lipid barrier. We hypothesized that JAKi A, B and C could restore the epidermal barrier in both HI three-dimensional (3D) organotypic models (OTs) made using ABCA12 CrispR-Cas9 knockout and wild-type keratinocytes and ARCI 3D OTs generated with short hairpin RNA knock down of TGM1. The JAKi were tested at three concentrations in the 3D models (20, 50 and 500 nmol L–1 for JAKiA; 10, 50 and 250 nmol L–1 for JAKiB; 2, 25 and 125 nmol L–1 for JAKiC) and vehicle only was used as the control. The OTs were stained with haematoxylin and eosin, Nile red and differentiation markers such as K10, K14, transglutaminase 1 (TGM1) and involucrin. All three JAKi had a positive effect on the epidermal barrier. The epidermal structure looked more organized and uniform, with an increase in neutral and polar lipids in the upper epidermis. The differentiation markers showed normalization of the expression of involucrin, K10 and TGM1 at the same drug concentrations. These results suggest that JAKi have a generalized positive effect on the skin barrier and will be further investigated in an in vivo mouse model of HI.
P04 Skin concentration of 7-dehydrocholesterol is not a limiting factor for vitamin D3 synthesis in older versus younger adults, and a similar response occurs to UVR in these age groups
Authors: Oktawia Borecka, John J Dutton, Jonathan C Y   Tang, William D Fraser, Lesley E Rhodes
Journal: British Journal of Dermatology (2023)

Abstract Skin exposure to ultraviolet radiation (UVR) triggers conversion of precursor 7-dehydrocholesterol (7DHC) to vitamin D3, which then enters the bloodstream. The aim of this study was to assess if skin 7DHC concentration differs between younger and older adults, and to explore the impact of solar-simulated UVR (SSR) on 7DHC (in skin) and vitamin D3 (cholecalciferol; in serum) in these age groups. Younger (n = 10, 18–40 years) and older (n = 11; 65–89 years) adults of skin phototype I–III were exposed to a suberythemal dose of SSR (95% UVA, 5% UVB, 1.3 standard erythemal dose) over 35% body surface area in the UK winter. Six 5-mm buttock skin punch biopsies were taken: two from unexposed skin, two immediately post-UVR and two at 24 h post-UVR. Blood was taken at baseline, 24 h and 7 days post-UVR. Skin and serum samples were assayed using high-performance liquid chromatography–tandem mass spectrometry. Baseline mean (SD) 7DHC concentrations were 0.22 (0.07) µg mg–1 and 0.25 (0.08) µg mg–1 in younger and older adults, respectively. Immediately post-UVR, 7DHC concentrations were 0.27 (0.10) µg mg–1 and 0.22 (0.08) µg mg–1 in younger and older adults, respectively, and 24 h post-UVR they were 0.27 (0.08) µg mg–1 and 0.28 (0.13) µg mg–1, respectively. Baseline serum vitamin D3 concentrations in younger adults were 1.5 (1.5) nmol L–1 vs. 1.5 (1.7) nmol L–1 in older adults; 24 h post-UVR they were 3.1 (2.0) nmol L–1 in younger adults vs. 2.5 (2.0) nmol L–1 in older adults and 7 days post-UVR they were 2.0 (2.1) vs. 1.7 (1.2) nmol L–1, respectively. No significant difference was seen in any parameter between age groups. Thus, in contrast to previous assumptions, skin 7DHC concentration is not a limiting factor for vitamin D3 synthesis in healthy older adults relative to younger adults. The early vitamin D3 biosynthetic pathway does not appear to differ between these age groups.